Cao Zhipeng, Oh Sukhoon, Sica Christopher T, McGarrity John M, Horan Timothy, Luo Wei, Collins Christopher M
Department of Bioengineering, The Pennsylvania State University, Hershey, Pennsylvania, USA; Department of Radiology, The Pennsylvania State University, Hershey, Pennsylvania, USA.
Magn Reson Med. 2014 Jul;72(1):237-47. doi: 10.1002/mrm.24907. Epub 2013 Sep 4.
To describe and introduce new software capable of accurately simulating MR signal, noise, and specific absorption rate (SAR) given arbitrary sample, sequence, static magnetic field distribution, and radiofrequency magnetic and electric field distributions for each transmit and receive coil.
Using fundamental equations for nuclear precession and relaxation, signal reception, noise reception, and calculation of SAR, a versatile MR simulator was developed. The resulting simulator was tested with simulation of a variety of sequences demonstrating several common imaging contrast types and artifacts. The simulation of intravoxel dephasing and rephasing with both tracking of the first order derivatives of each magnetization vector and multiple magnetization vectors was examined to ensure adequate representation of the MR signal. A quantitative comparison of simulated and experimentally measured SNR was also performed.
The simulator showed good agreement with our expectations, theory, and experiment.
With careful design, an MR simulator producing realistic signal, noise, and SAR for arbitrary sample, sequence, and fields has been created. It is hoped that this tool will be valuable in a wide variety of applications.
描述并介绍一款新软件，该软件能够针对任意样本、序列、静磁场分布以及每个发射和接收线圈的射频磁场和电场分布，精确模拟磁共振（MR）信号、噪声和比吸收率（SAR）。
利用原子核进动和弛豫、信号接收、噪声接收以及SAR计算的基本方程，开发了一款通用的MR模拟器。通过对多种序列进行模拟测试该模拟器，这些序列展示了几种常见的成像对比类型和伪影。研究了体素内去相位和重相位的模拟，同时跟踪每个磁化矢量的一阶导数以及多个磁化矢量，以确保对MR信号有足够的表示。还对模拟的和实验测量的信噪比进行了定量比较。
该模拟器与我们的预期、理论和实验结果吻合良好。
经过精心设计，已创建出一款能为任意样本、序列和场生成逼真信号、噪声和SAR的MR模拟器。希望该工具在众多应用中具有重要价值。
